Chromium hazard removal by immobilized biomass of saccharomyces cerevisiae NRRL 567

The immobilization of Saccharomyces cerevisiae NRRL 567 biomass has been used to demonstrate its potential for removal and recovery of chromium ions from waste water streams. The immobilization process was carried out using three different immobilizing agents namely; Ca alginate, polyacrylamide and silica gel. Tris-HCI [pH 7.2] was the most suitable buffer for chromium removal on using the tested immobilizing agents. Ca alginate 3%, at residence time 30 min offered high removal of chromium ions [81.1%]. However, silica gel was found to be the best immobilizing agent, since 91.6% of chromium ions were removed. Furthermore, on increasing the dry weight of the used S. cerevisiae up to 50 mg/ml of the buffered chromium solution, the amount of the removed chromium ions reached about 97%. Elution of loaded chromium ions from the yeast cells immobilized on silica gel was successively achieved using 1% EDTA solution. Similarly, HCI and H[2]SO[4] solutions were found to be efficient in releasing chromium ions

Studies on some factors influencing the production of calcium lactobionate by Pseudomonas mucidolens NRRL B-16

The effect of some factors on calcium lactobionate production by P. mucidolens NRRL B-16 using the submerged culture technique was investigated. It was found that optimum yield of calcium lactobionate [65%] was obtained when the culture medium contained [g/L], lactose 100, KH2PO4 0.6, MgSO4.7H2O 0.25, corn steep liquor 5 ml, calcium carbonate 2.5 g/100 ml, 1 ml/100 ml of 20% urea and 3 drops of soybean oil/100 ml as an antiforming agent at an initial pH of 7 after 14 days of incubation at 30C

Microbial response to steroids

The metabolic activities of Aspergillus nidulans culture able to oxygenate progesterone [P] at C-6 beta; 11 alpha and 21-positions, responded differently to the added P. Thus, a rapid sugar and a limited nitrogen uptakes leading to the accumulation of lipid materials was recorded in the presence of P. Similarly, the detailed analysis of nucleic acids, amino acids, fatty acids and sterol constituents revealed different profiles when P was supplemented to the fermentation medium

Nitrogen fixation by some locally isolated bacteria

Several bacterial isolates were tested for their potentiality to fix atmospheric nitrogen. Azomonas macrocytogenes was selected as the experimental organism because of the paucity of knowledge on the N[2] fixation by this organism. Total N[2]fixed was obtained with the modified Winogradsky N[2]free medium. Glucose was superior among the different carbon sources tested, supporting the highest value of total N[2]fixed. The essential amino [except cystine] were detected both within the cells as well as in the culture broth. Low levels of ammonia were found in the cell exudates, whereas relatively higher yields were detected intracellularly

Riboflavin formation by some mold fungi cultivated on hydrocarbon containing media

The potentiality of some mold fungi isolated from petroleum sludge-to produce riboflavin when grown on hydrocarbon-containing media was tested. Aspergillus terreus was found to be distinguished by its capacity to produce riboflavin when cultivated on the different culture media tested. It was able to grow more luxuriantly and produce good riboflavin output on solar containing medium. Solar concentration of 5% v/v favoured high riboflavin productivity. However, maximal B[2]yields were achieved after 20 days incubation at 30?C. Initial pH value of 5.5-6.0 was found to be optimum for growth of A. terreus and its riboflavin production